If you read this documentation, it says-
The
og.likes
action can refer to any open graph object or URL, except for Facebook Pages or Photos.
So, liking a page with Graph API isn't possible.
I think you have just 2 alternatives-
You can load the FB page in the FB application and make the user able to like the page from there.
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"fb://profile/{page-id}"]];
You can use a
UIWebView
and add a Like Button.
You can also check this: FacebookLikeView